The invention is an improvement upon the invention described in prior U.S. Pat. No. 4,459,894, the disclosure of which is incorporated by reference herein as if set forth at length. The Phalanx gun is the gun currently used by the Navy to shoot down incoming cruise missiles by tracking the missile and accurately firing a barrage of high velocity armor-penetrating projectiles at the missile until it is destroyed. Inaccuracy of the gun or ammunition could conceivably lead to the projectiles missing the missile with resultant loss of an aircraft carrier or other extremely vital naval vessel together with its crew. The conventional Phalanx ammunition round includes a sophisticated projectile. The projectile has a depleted uranium core ("penetrator") designated to penetrate metallic armour within a surrounding light plastic "sabot" designed to seal the depleted uranium from the environment until the projectile is launched and allow the penetrator to be fired from a large diameter barrel bore so as to have the propelling pressure act over a bigger area and thus produce a bigger force on the penetrator which in turn gives greater acceleration and ultimately higher velocities to the penetrator. The projectile also has a pusher plug designed to impart spin to the penetrator to enhance penetration and designed to protect the penetrator from contact by the hot propellant gases during firing. In order to minimize cost and parisitic weight, this pusher plug is conventionally aluminum and has a ringshaped rotating band around it to protect the gun barrel from aluminum fouling which might otherwise occur if the aluminum pusher plug were to directly contact the barrel bore. In order to be most effective, it is necessary that the rotating band, penetrator (projectile core), pusher plug and sabot all be aligned with each other, and especially the rotating band and projectile core. If the core and band are misaligned even slightly, the spin-up of the projectile about the axis of the rotating band will result in wobbling of the core and resultant inaccuracy. The present invention has effectively minimized "balloting" (wobble in the barrel) and "coning" (wobbling in flight) due to the misalignment above noted and has done so at reduced cost, thus allowing for more rounds of better ammunition to be acquired within the same defense budget. The present invention further improves upon the method of U.S. Pat. No. 4,459,894 by doing this in a manner which is practical for high volume production.
The invention achieves this end by providing a manufacturing method in which the core, sabot, plug and band are all simply, effectively and automatically aligned with each other so that misalignment is effectively eliminated. The invention also allows for an unstressed sabot in contrast to the conventional sabot which is highly stressed when assembled. High sabot stresses before loading and firing are advantageouly avoided by the invention thus eliminating conventional misalignments caused by uneven stress-strain properties within the sabot. A special alignment ring insures alignment of the penetrator with the rotating band and sabot mold during molding of the sabot.